HLIBpro  3.0
TJacobi< T_value > Class Template Reference

implements Jacobi preconditioner More...

#include <TJacobi.hh>

Inheritance diagram for TJacobi< T_value >:
TLinearOperator< T_value > TTypeInfo

Public Member Functions

 TJacobi (const TMatrix< value_t > *A, const real_t damping=real_t(1), const size_t block_size=1, const TTruncAcc &acc_block=acc_exact)
 
const TMatrix< value_t > * matrix () const
 return sparse matrix
 
real_t damping_factor () const
 return damping factor
 
bool is_complex () const
 return true, if field type is complex
 
bool is_self_adjoint () const
 return true, of operator is self adjoint
 
virtual void apply (const TVector< value_t > *x, TVector< value_t > *y, const matop_t op=apply_normal) const
 
virtual void apply_add (const value_t alpha, const TVector< value_t > *x, TVector< value_t > *y, const matop_t op=apply_normal) const
 
virtual void apply_add (const value_t alpha, const BLAS::Vector< value_t > &x, BLAS::Vector< value_t > &y, const matop_t op=apply_normal) const
 
virtual size_t domain_dim () const
 return dimension of domain
 
virtual size_t range_dim () const
 return dimension of range
 
virtual auto domain_vector () const -> std::unique_ptr< TVector< value_t > >
 return vector in domain space
 
virtual auto range_vector () const -> std::unique_ptr< TVector< value_t > >
 return vector in range space
 
- Public Member Functions inherited from TLinearOperator< T_value >
virtual bool is_real () const
 return true, if field type is real valued
 
- Public Member Functions inherited from TTypeInfo
virtual typeid_t type () const =0
 return type ID of object
 
virtual bool is_type (const typeid_t t) const
 return true if local object is of given type ID t
 
virtual std::string typestr () const
 return string representation of type
 

Detailed Description

template<typename T_value>
class Hpro::TJacobi< T_value >

     TJacobi provides application of a Jacobi type preconditioner for a given
     matrix A, e.g. \f$ D^{-1} \f$ with \f$D\f$ being the diagonal of A. Here, 
     A may be of any type, e.g. dense, low-rank, block or sparse matrix. The
     diagonal elements are assumed to be non-zero.

     Also support block-wise mode, i.e., diagonal blocks are inverted. For this,
     the size of diagonal block is defined during construction. If this equals 1
     point-wise Jacobi is used. Please note, that for block-wise mode, the leaf
     blocks define the smallest block size.

Constructor & Destructor Documentation

◆ TJacobi()

TJacobi ( const TMatrix< value_t > *  A,
const real_t  damping = real_t(1),
const size_t  block_size = 1,
const TTruncAcc acc_block = acc_exact 
)

construct Jacobi preconditioner based on matrix A with damping factor damping

Member Function Documentation

◆ apply()

virtual void apply ( const TVector< value_t > *  x,
TVector< value_t > *  y,
const matop_t  op = apply_normal 
) const
virtual

mapping function of linear operator \(A\), e.g. \( y := A(x)\). Depending on op, either \(A\), \(A^T\) or \(A^H\) is applied.

Implements TLinearOperator< T_value >.

◆ apply_add() [1/2]

virtual void apply_add ( const value_t  alpha,
const BLAS::Vector< value_t > &  x,
BLAS::Vector< value_t > &  y,
const matop_t  op = apply_normal 
) const
virtual

same as above but only the dimension of the vector spaces is tested, not the corresponding index sets

Implements TLinearOperator< T_value >.

◆ apply_add() [2/2]

virtual void apply_add ( const value_t  alpha,
const TVector< value_t > *  x,
TVector< value_t > *  y,
const matop_t  op = apply_normal 
) const
virtual

mapping function with update: \( y := y + \alpha A(x)\). Depending on op, either \(A\), \(A^T\) or \(A^H\) is applied.

Implements TLinearOperator< T_value >.